import java.util.LinkedList;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class Monitor {

   private LinkedList<Soknad>[] lister = new LinkedList[10];
   private int antall = 0;
   private Lock laas = new ReentrantLock();
   private Condition ingenSoknader = laas.newCondition();
   private int antallBehandlere;

   public Monitor(int antallBehandlere){
       this.antallBehandlere = antallBehandlere;
       for(int i = 0; i < lister.length; i++){
           lister[i] = new LinkedList<Soknad>();
       }
   }

   public void leggTil(Soknad soknad){
       laas.lock();
       try{
           if(soknad == null) {
               antallBehandlere--;
               if(antallBehandlere == 0) ingenSoknader.signalAll();
               return;
           }
           lister[soknad.hentPrio()].add(soknad);
           antall++;
           ingenSoknader.signalAll();
       }finally{
           laas.unlock();
       }
   }

   public Soknad taUtSoknad(){
       laas.lock();
       try {
           while(antall < 1) {
               if(antallBehandlere == 0) return null;
               ingenSoknader.await();
           }
           antall--;

           int teller = 0;
           //antar at det må finnes noe
           while(lister[teller].isEmpty()) teller++;
           return lister[teller].remove(0);
       } catch (Exception e) {
           return null;
       }finally{
           laas.unlock();;
       }
   }
    
}